1. Field of the Invention
The present invention relates to a rotational position detecting device for detecting rotational position, angle or rotational speed of the crank shaft or the cam shaft of an internal combustion engine.
2. Description of the Related Art
Conventional rotational position detecting devices are disclosed in Japanese Utility Model Unexamined publication Hei 3-48715 and Japanese Patent Unexamined Publication Hei 4-346070. The former discloses a sensor unit utilizing a pair of Hall elements to detect rotational position of a rotational member, and the latter discloses a circuit to detect peaks of signals of a sensor.
However, such combined device cannot detect normal peak voltage just after a power switch is turned on to energize the above devices combined together, thereby causing engine problems especially when the device is applied to detect each cylinder of an engine.